2. Photosynthesis is broken down into 2 parts: The Light Dependent Reactions: require sunlight; produce ATP, NADPH and O 2 The light Independent ( a.k.a. Dark Reactions or the Calvin Cycle ): does not require sunlight; produces glucose

3. Both the light dependent reactions and the light independent reactions occur within the chloroplasts of plant cells.

4. Anatomy of the chloroplast (see figure 6-8. page 118) Composed of 3 membranes: 1. Outer membrane 2. Inner membrane (just below the outer membrane) 3. Thylakoid (photosynthetic) membrane (in the middle)

5. Outer Membrane Intramembrane Space Inner Membrane Stroma Thylakoid Membrane (Photosynthetic membrane) Thylakoid Space Chloroplast Anatomy

7. The light dependent reactions can be divided into four basic processes: Light absorption Electron transport Oxygen production ATP formation

11. 1.Electrons ( e -s ) in chlorophyll are excited by solar energy. 2. These excited e -s leave the chlorophyll and are passed through a series of molecules (known as the electron transport chain) and eventually end up in NADPH.

17. 3. NADPH is now excited (carrying extra energy) and will be used later in the dark reactions to produce glucose. 4. e -s, which chlorophyll looses (to the e - transport chain) are replaced with e -s from water. The splitting of water: 2H 2 O 4H + + 4e -s + O 2 5. The H + is pumped (active transport) across the photosynthetic membrane creating an area of high concentration of H +.

18. The Electron Transport Chain (e - tc)

19. 6. This area of high concentration is potential energy and has the ability to do work. 7. As H + s fall down their concentration gradients, they move across the photosynthetic membrane through an enzyme called ATP synthase. 8. ATP synthase makes ATP that will be used later in the light independent reactions to produce glucose.

20. Summary of the Light Dependent Reactions Use light as an energy source Occur in the photosynthetic membrane Produce ATP and NADPH that are used in the dark reactions to make glucose. Use e -s from water to replace those lost by chlorophyll. Produce O 2 as a byproduct.

22. 1.Do not require light to occur, but can occur in the presence of light. 2.Known as the Calvin Cycle (see fig. 6-13) 3.Uses the energy in ATP and NADPH (from the light reactions) to fix carbon.

23. 4. CO 2 is an inorganic compound. C 6 H 12 O 6 is an organic compound. Incorporating an inorganic compound into an organic compound is known as Fixation. 5. Each turn of the Calvin Cycle makes a 3-carbon compound. Therefore, 2 turns of the Calvin Cycle are needed to produce one glucose molecule.

25. Summary equation of the Light Independent Reactions 6 CO 2 + ATP + NADPH C 6 H 12 O 6 + ADP + NADP + The ADP AND NADP + are returned to the light reactions to be reenergized.

26. He earned the Nobel prize for determining the biochemical pathway used to make glucose Melvin Calvin